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View Full Version : stripped my hub installing new rear sprocket


moparrob
10-29-2016, 01:36 AM
So I went ahead and got the new (flat, non-dished) 47 tooth rear sprocket for my TT250 and decided to install it tonight. Due to the flat sprocket you need to use .300 shims behind the sprocket to space it out to the distance of the stock, dished sprocket.

I didn't realize when I re-installed it that I would be losing .300 of purchase of the 10mm bolt threads on the shaft of the bolt, due to the shim thickness, which left about .310 of bolt sticking into the hole (which, by the way is 1.270 deep). I over-torqued the bolts when re-installing them and stripped all of the four 10mm holes out.:ohno:

So my thought is to get a 10x1.25 tap and clean up the first .310 of compromised threads and then buy four new bolts with enough length to take advantage of the existing 1.270 deep threaded holes and screw them down (and hope they hold).

Does anyone have any better ideas or input before I tackle this tomorrow?

pete
10-29-2016, 02:12 AM
If you have no luck with the longer bolts...
tap the 10mm holes to 9/16" is 11mm...
drill the sprocket holes...



...

moparrob
10-29-2016, 02:14 AM
If you have no luck with the longer bolts...
tap the 10mm holes to 9/16" is 11mm...
drill the sprocket holes...

...
Yeah, I figured I could do that if necessary but I do not have a mill and want to avoid drilling off center if I can avoid it. Thanks.

pete
10-29-2016, 03:05 AM
most lightly wouldn't have to drill the hole out...
run the tap straight into the striped hole..



.

moparrob
10-29-2016, 03:15 PM
Glad to say I fixed it. I ended up finding the only grade 8 bolts in town and cleaned up the threads before installing them. It seems like everything is good for now. Thank you for the help.